The results of the study in which Williams participated were released today. And it turns out that what's helpful for wrinkles appears to be good for leaky bladders, as Botox might be as good as or even better than standard medications used to treat bladder leakage.

The clinical trial, published in the New England Journal of Medicine, involved nearly 250 women with leaky bladders. Half the women received a Botox treatment to their bladders and a six-month supply of placebo pills. The other half received medication useful for treating leaky bladders and a saltwater injection instead of Botox. Neither the women nor the doctors knew who was getting what treatment.

The researchers monitored their leaky bladder symptoms and treatment side effects. What they found was that, in a six-month period, one Botox bladder treatment worked as well as daily pills to reduce daily bladder leakage. Moreover, women who got Botox were twice as likely to have their leaky bladder symptoms disappear when compared to women who took pills.

Leaky bladders -- also known as urge incontinence -- are caused by an overactive bladder muscle that contracts without warning leading to unexpected urine leakage, said lead study author, Dr. Anthony G. Visco, chief of the division of urogynecology and reconstructive pelvic surgery at Duke University Medical Center in Durham, N.C.

Leaky bladders affect nearly one in five older women across the United States. Women are twice as likely to be affected, compared to men.

Think of the bladder like a water balloon, Visco said. "The bladder itself is lined by a muscle," he said. "When that muscle contracts, our bladders empty."

In leaky bladders, he said, that muscle contracts on its own and unexpectedly.

"Botox works by relaxing or paralyzing that muscle," he said. "We try to use Botox to bring that [bladder muscle] back into balance."

Dr. Erika H. Banks, director of gynecology at Montefiore Medical Center and associate professor at Albert Einstein College of Medicine in New York City, who was not involved with the study, said, "It's impressively effective."

There are side effects, she said, but "if [patients] get relief, then it's worth it."

Despite the positive news from the study, however, Botox for urge incontinence will likely face several hurdles. One issue is that Botox is not approved by the Food and Drug Administration for treating this condition. Another hurdle, Visco said, is the potentially high price tag, which could run hundreds or even thousands of dollars.

"Even though it's a reasonable treatment option," he said, "it's prohibitively expensive for the average person to pay for it at this time."

There are side effects; one in three of the Botox users in the study developed urinary tract infections, and 5 percent of the Botox users needed to temporarily use a catheter to empty their bladders.